Fluid pressure braking apparatus



March 12, 1935. T. TARISIEN 1,994,182

FLUID PRESSURE BRAKING APPARATUS Filed Aug. 4, 1933 INVE N TO RTHEOPHILEI TARISIEN ATTORNEY Patented Mar. 12, 1935 PTATENTYYOFFIQE1,994,132 a FLUID PRESSURE BRAKING APPARATUS: 1 Theophile Tarisien,Livry-Garg an, France; as-

signor to Westinghouse Air Brake Company, Wilmerding, Pa., a corporationof Pennsylvania Application August 4, 1933, ScriaLNo. 685,586

In Great Britain August 13 1932 6 Claims. (01. 303-8 1) This inventionrelates to fluid pressure brak ing apparatus of the kind comprisingatriple or other form of distributing valve device adapted to effect theapplication of the brakes by the 5 supply of fluid under pressure to thebrake cylinder or' cylindersof the apparatus in two stages,

during the first of which the supply of fluid is relatively unrestrictedso as to cause a rapid application of the brake blocks to the wheels,while during the second stage the flow of fluid to the brakecylinder orcylinders is relatively restricted so as to cause a gradual building upof thed'esired pressure.

Distributing valves of this character as hitherto constructed haveusually comprised a regulating valve interposed inthe path of the flowof fluid to the brake cylinder or cylinders, this valve being normallymaintained in its open position by an abutment subject on one side tothe action of a controlling spring. The opposite sideof the abutment isarranged to be subject to the pressure obtaining in the brake cylinder,so that, as soon as this pressure has built up to a value suifi cienttoovercome the action of the controlling spring the abutment is moved topermit closure of the regulating valve, the subsequent. flow of fiuidunder pressure to the brake cylinder taking place througha relativelyrestricted port.

The invention has for its principal object to provide an improvedregulating valve of the character above indicated in which theabutmentoi the valve is arranged to besubject to a controlling fluidpressure which is a definite predetermined'fraction of the normal fluidpressure ch- 35 taining in the system, thus dispensing with'the use of acontrolling spring as has hitherto been customary. I

In order that the invention may be readily understood a preferredembodiment thereof will now be described with reference to theaccompanying drawing as applied to V a triple valve device of otherwiseknown construction.

Referring now to the single figure of'the accompanying drawing, thetriple valve comprises 45 a casing 1 containing a valve chamber 2 and apiston chamber 3, the latter containing a piston 4 adapted to actuate aslide valve 5 provided with the usual ports and cavities and containinga graduating valve 6. Mounted on one side of the casing is anaccelerating bulb or chamber 7 which communicates through a passage 8with a port 9 in the seat of the slide valve. In the release position ofthe triple valve piston, as shown in the single figure of the drawingthe port 9 is arranged 55 to be in communication with the atmosphere byhereinbefore and a port 31 in the slide valve seat way of. a cavitylO inthe slide valve 5 and an atmospheric-port 11. The valve chamber 2 is inopen communication with the-auxiliary reservoir (not ShOWIliiIllthdrawing) in the usual manner, the piston-chamber 3 being: incommunication 5 with the trampipe 24 of the apparatus. A port 12 in thetriple valve casing =1 communicates with thebrake cylinder (not shown inthe drawing) and the 'said casing'is providedwith a rotary plug cock"13having-a calibrated-orifice 14 therein. 10 Arranged below theiplug cock13 is a controlling valve '15'which is normally open, and the seat 16 ofthe said controlling v'alve is provided with arestricted by-pass'orificel'l.

V The controlling valve 15 is arranged to be norl5 mallymaintainediniits open position by means of-- a-diaphragm l8 subjectonits'uppe'r side to communicating with the brake cylinder, thediaphragm 18 being subject on its lower side normally 1 to the fluidpressure obtaining a diaphragm chamber 21 which under release conditionsas shown in the single figurei of'the drawing is incommunication-through a passage 22 in the triple Lvalve casing 1 andaport 23 in the slide valve seatwith the slidevalve chamber 2.- Undera'pplication. conditions the. diaphragm' chamber 21 l is incommunication with an expansion chamber 30,

25 through passages 22 and 26 in thetriple valve casing and a, cavity27in the slide valve 5, which cavity serves under release conditions asshown in the drawing to; establish communication between the. expansionchamber 25 and an atmos- 35 pheric port 28. z v

The operation of the apparatus is as follows: Under release conditionsthe triple valve piston and slide valveare in their left hand positionsas shown :in the drawing in which the graduating valve 6 is closed ,andthe brake cylinder is in communication with an atmospheric port 29through" a recess 30 in the slide valve. Moreover the accelerating bulbor chamber '7 is in communication with the atmospheric port 11, asdescribed which ,is in communication with the train pipe 24 is blankedby the slide valve 5; the diaphragm chamber'2l is'in:communication withthe slide valve chamber 2 and the expansion chamber 25 with theatmospheric port 28.

Whenthe train pipe pressure is reduced in order to eiiectan applicationoflthe brakes, the triple valve piston 4 is :moved to the right, firstlifting the graduating valve 6 from its seat and then shifting the slidevalve 5 to its right hand or application position, the movement of thepiston 4' and slide valve 5 being accelerated owing to communicationbeing established between the port 31 in the slide valve seat which isin communication with the train pipe 24, and the port 9 in the slidevalve seat. which is in communication with the bulb 7, thiscommunication being established through the recess 10in the slide valve5. In the right hand or application posi tion of the slide valve 5 therecess 27 in the slide valve establishes communication between theexpansion chamber 25 and the diaphragm chamber 21'with the result thatthe diaphragm 18 is subject underneath to only a fraction of theauxiliary reservoir pressure, the value of this fraction being dependentupon therelative vol ,umes of the diaphragm and expansion chambers 21,25. In the application position of the slide valve fluid under pressureis supplied from the auxiliary reservoir through the slide valve chamber2and past the vunseated graduating valve 6 to the brake cylinder througha passage.32 in the casing 1 of the triple valve; The flow of fluid tothe brake cylinder follows. two paths, the first traversing thecalibrated orifice -14 in the plug cook 13 and-the second traversing thecontrolling valve 15 referred to hereinbefore and the calibrated orifice17in the seat 16 of said valve.

Fluid is therefore supplied relatively rapidly to the brake cylinder soas to applythe'brake blocks,

downwardly and permits the controlling valve" 15 to seat. Thereafterfluid is supplied tothe' brake cylinder through the two calibratedorifices 14 and 17 only so as. graduallyto build up the r i a chamber incommunication with the opposite side of said abutment, means forsupplying'fluid braking pressure. 1

It will be evident that the invention is notlimited to the particularconstruction and arrangements of the parts hereinbefore described which.may ,be varied as desired to suit particular requirements withoutexceeding the scope .of-"the invention.

Having now described my invention, what I claim as new and desire tosecure by Letters Patent is:-

'1. A valve devicefor regulating the flow of fluid under .pressure tothe brake cylinder of fluid pressure braking apparatuscomprising incombi nation a movable abutment subject on one side to the pressure inthe brake cylinder, means for subjecting the opposite side of saidabutment to a pressure which is substantially constant while the brakesare being applied and which is a predetermined fraction of the normalpressure in said braking apparatus, and a valve operated by saidabutment for controlling the flow of fluid pressure in the brakecylinder, means for subjecting the opposite side of said abutment'duringthe release of the brakes, to the normal pressure obtaining in theapparatus, means for subjecting this side of the abutment to asubstantially constant pressure which is a predetermined fraction ofsaid normal pressure during the application of the brakes, and a valveoperatedby said abutment for controlling the flow of fluid to the brakecylinder. 7 p r 3. A valve device for regulating the flow of fluid underpressure to the brake cylinder of fluid pressure braking apparatuscomprising in combina- 5 tion a movable abutment subject on one sideto isubjecting this side'of said abutment to a different pressure from saidnormal pressure which is substantially constant during. the applicationof the brakes, and arvalve operated by said abutvment for controllingthe flow of fluid to the brake cylinder.

4. The combination in fluidpressurebraking 7 apparatus of a distributingvalve having a release I position and anapplication position, aregulating valve forcontrolling the supplyof fluid under pressure to thebrake cylinder of the apparatus through said distributing valve, amovable abutment for operating said regulating valve and subject on oneside to the pressure in said brake cylinder, means for supplying fluid.at one predetermined pressure to the opposite side of said abutmentwhen the distributing valve is in its 2 release position and means forsubjecting the opposite side of said abutment to a different pree j soff determined fluid pressure which remains-sub stantially constant whensaid distributing valve is in its application position. i.

5. The combination in fluid pressure braking apparatus of a distributingvalve having, a release position and an application position,a'regulating valve for controlling the" supply of fluid under pressureto the brake cylinder of the appa on,one side ,to the pressure in saidbrake cylinder;

at a predetermined pressure to said chamber when said distributing valveis in its release posi- 1 tion, a second chamber and means for cuttingoff" the supply of fluid to said first chamber and for establishingcommunication between said cham-1, H

bers when said distributing valve is in its application position toprovide a substantially constant pressure less'than said predeterminedpressure in the chamber in communication with said opposite side of theabutment. 1

6. The combination in fluid pressure braking apparatus of a distributingvalve having a' release position and an application position, a'regulating valve for controlling the supply of fluid under pressure tothe, brake cylinder of the v apparatus through said distributing valve,a movable abutment for operating said valve and subject on one side tothe pressure in. said brake cylinder, a chamber in communication withthe opposite side of said abutment, a second chamber,

' means for supplying fluid under pressure to said first chamber and forventing said second chamber when said distributing valve is in itsrelease,

position and means for cutting off thesupplyi of fluid under pressuretosaid first chamber and for establishing communication betweensaid"chambers when said distributing valve is inv its applicationposition toprovide in said first chamher a pressure which remains substantiallyconstant while the brakes are applied.

THEOPHILE TARISIEN. I j i

